I would like to comment on the range options of the current stormcast units.
The example of the Tempestors and the Crossbow Judicators is a moot point as a 12inch range is no ranged threat and with the stats it has they actually can't do any notable damage. Specifically the Tempestors crossbows are for their -1 to hit debuff rather than actually killing anything...
The Judicators with the longbows are a very decent unit, but their main saving grace is that they are battleline. Other-wise I don't see them at 160pts being that mauch of a threat as they do an average of 3 wounds on a 4+ save unit. For these points there are better shooting units out there.
The Prosecutors with javelins are nice but if your shooting unit must enter 18 inches in order to shoot you very much risk them getting charged, arcane bolted etc...
That said I do not feel the need for more shooting units for stormcasts, but as daedalus81 has said some speed and some long range shooting will help get the Stormcasts away from the need to do Warrior Brotherhood all the time...